1 /* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Copyright (C) 2006 by Ralf Baechle (ralf@linux-mips.org) 7 */ 8 #ifndef __ASM_BARRIER_H 9 #define __ASM_BARRIER_H 10 11 #include <asm/addrspace.h> 12 13 #define read_barrier_depends() do { } while(0) 14 #define smp_read_barrier_depends() do { } while(0) 15 16 #ifdef CONFIG_CPU_HAS_SYNC 17 #define __sync() \ 18 __asm__ __volatile__( \ 19 ".set push\n\t" \ 20 ".set noreorder\n\t" \ 21 ".set mips2\n\t" \ 22 "sync\n\t" \ 23 ".set pop" \ 24 : /* no output */ \ 25 : /* no input */ \ 26 : "memory") 27 #else 28 #define __sync() do { } while(0) 29 #endif 30 31 #define __fast_iob() \ 32 __asm__ __volatile__( \ 33 ".set push\n\t" \ 34 ".set noreorder\n\t" \ 35 "lw $0,%0\n\t" \ 36 "nop\n\t" \ 37 ".set pop" \ 38 : /* no output */ \ 39 : "m" (*(int *)CKSEG1) \ 40 : "memory") 41 #ifdef CONFIG_CPU_CAVIUM_OCTEON 42 # define OCTEON_SYNCW_STR ".set push\n.set arch=octeon\nsyncw\nsyncw\n.set pop\n" 43 # define __syncw() __asm__ __volatile__(OCTEON_SYNCW_STR : : : "memory") 44 45 # define fast_wmb() __syncw() 46 # define fast_rmb() barrier() 47 # define fast_mb() __sync() 48 # define fast_iob() do { } while (0) 49 #else /* ! CONFIG_CPU_CAVIUM_OCTEON */ 50 # define fast_wmb() __sync() 51 # define fast_rmb() __sync() 52 # define fast_mb() __sync() 53 # ifdef CONFIG_SGI_IP28 54 # define fast_iob() \ 55 __asm__ __volatile__( \ 56 ".set push\n\t" \ 57 ".set noreorder\n\t" \ 58 "lw $0,%0\n\t" \ 59 "sync\n\t" \ 60 "lw $0,%0\n\t" \ 61 ".set pop" \ 62 : /* no output */ \ 63 : "m" (*(int *)CKSEG1ADDR(0x1fa00004)) \ 64 : "memory") 65 # else 66 # define fast_iob() \ 67 do { \ 68 __sync(); \ 69 __fast_iob(); \ 70 } while (0) 71 # endif 72 #endif /* CONFIG_CPU_CAVIUM_OCTEON */ 73 74 #ifdef CONFIG_CPU_HAS_WB 75 76 #include <asm/wbflush.h> 77 78 #define mb() wbflush() 79 #define iob() wbflush() 80 81 #else /* !CONFIG_CPU_HAS_WB */ 82 83 #define mb() fast_mb() 84 #define iob() fast_iob() 85 86 #endif /* !CONFIG_CPU_HAS_WB */ 87 88 #define wmb() fast_wmb() 89 #define rmb() fast_rmb() 90 #define dma_wmb() fast_wmb() 91 #define dma_rmb() fast_rmb() 92 93 #if defined(CONFIG_WEAK_ORDERING) && defined(CONFIG_SMP) 94 # ifdef CONFIG_CPU_CAVIUM_OCTEON 95 # define smp_mb() __sync() 96 # define smp_rmb() barrier() 97 # define smp_wmb() __syncw() 98 # else 99 # define smp_mb() __asm__ __volatile__("sync" : : :"memory") 100 # define smp_rmb() __asm__ __volatile__("sync" : : :"memory") 101 # define smp_wmb() __asm__ __volatile__("sync" : : :"memory") 102 # endif 103 #else 104 #define smp_mb() barrier() 105 #define smp_rmb() barrier() 106 #define smp_wmb() barrier() 107 #endif 108 109 #if defined(CONFIG_WEAK_REORDERING_BEYOND_LLSC) && defined(CONFIG_SMP) 110 #define __WEAK_LLSC_MB " sync \n" 111 #else 112 #define __WEAK_LLSC_MB " \n" 113 #endif 114 115 #define smp_store_mb(var, value) \ 116 do { WRITE_ONCE(var, value); smp_mb(); } while (0) 117 118 #define smp_llsc_mb() __asm__ __volatile__(__WEAK_LLSC_MB : : :"memory") 119 120 #ifdef CONFIG_CPU_CAVIUM_OCTEON 121 #define smp_mb__before_llsc() smp_wmb() 122 /* Cause previous writes to become visible on all CPUs as soon as possible */ 123 #define nudge_writes() __asm__ __volatile__(".set push\n\t" \ 124 ".set arch=octeon\n\t" \ 125 "syncw\n\t" \ 126 ".set pop" : : : "memory") 127 #else 128 #define smp_mb__before_llsc() smp_llsc_mb() 129 #define nudge_writes() mb() 130 #endif 131 132 #define smp_store_release(p, v) \ 133 do { \ 134 compiletime_assert_atomic_type(*p); \ 135 smp_mb(); \ 136 ACCESS_ONCE(*p) = (v); \ 137 } while (0) 138 139 #define smp_load_acquire(p) \ 140 ({ \ 141 typeof(*p) ___p1 = ACCESS_ONCE(*p); \ 142 compiletime_assert_atomic_type(*p); \ 143 smp_mb(); \ 144 ___p1; \ 145 }) 146 147 #define smp_mb__before_atomic() smp_mb__before_llsc() 148 #define smp_mb__after_atomic() smp_llsc_mb() 149 150 #endif /* __ASM_BARRIER_H */ 151